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Axios Network Error in React Native with Expo in Android

I'm trying to run an API call in React Native on Android with Expo using Axios, but I'm encountering a network error. I tried some solutions, but nothing seems to work. This is the error displayed in the console:
Network Error
at node_modules\\axios\\lib\\core\\AxiosError.js:3:0in \<global\>
at node_modules\\axios\\lib\\adapters\\xhr.js:138:8 in handleAbort
at node_modules\\event-target-shim\\dist\\event-target-shim.js:818:20 in EventTarget.prototype.dispatchEvent
at node_modules\\react-native\\Libraries\\Network\\XMLHttpRequest.js:647:10 in setReadyState
at node_modules\\react-native\\Libraries\\Network\\XMLHttpRequest.js:396:6 in didCompleteResponse
at node_modules\\react-native\\Libraries\\vendor\\emitter_EventEmitter.js:150:10 in EventEmitter#emit
at node_modules\\react-native\\Libraries\\BatchedBridge\\MessageQueue.js:417:4 in callFunction
at node_modules\\react-native\\Libraries\\BatchedBridge\\MessageQueue.js:114:6 in guard$argument_0
at node_modules\\react-native\\Libraries\\BatchedBridge\\MessageQueue.js:368:10 in guard
at node_modules\\react-native\\Libraries\\BatchedBridge\\MessageQueue.js:113:4 in callFunctionReturnFlushedQueue
I tried changing the localhost in the API link to my IP address, as well as to 10.0.2.2, but nothing worked. I checked my internet permission in AndroidManifest and made some other permission changes to the file, but nothing seemed to resolve it. I hope to find a solution to the problem soon.

if you are using a tool like expo go, [axiosError: Network error] is simply an error saying that the api you provided may not be reached.
so if you want to pull data from a local storage instead of cloud storage ... you may create a server like for example php artisan serve then create an Ngrok server for that server , afterwards take the link you received from the ngrok then use it as your new API endpoint

i m the same problem. you found solution l

Get url & parameters of a POST request made from an android app. (Hack an application)

1> Is it possible to fetch the end-point of a http post request made from an android app?
2> Is it possible to fetch the parameters (key & value) of that request ?
If it is not possible to fetch the exact end-point & the parameter list for a post request made from an android device, can we assume that it is very hard to hack that particular end-point?
Edit 1 :
Say, in my android app, I am using an end-point like - http://abc.xyz.com/buyItem with 2 parameters : itemCode=value1, price=value2
(how)Can the url, parameter list & values be fetched by a hacker?

Yes it is possible to monitor network traffic and get those values.
It is pretty easy to set-up with something like a basic (cheap) network hub (not a switch) and a PC attached and a few network tools like tcpdump or ngrep.
A tcpdump example would be:
tcpdump -A -i eth3 > t.dump
Change eth3 to your network interface. You can look over the file t.dump in a text editor or use less or more.
NOTE: SSL / HTTPS connections are encrypted, so tcpdump will only give you parameters over HTTP.
There are other ways as well.
You could get lucky and simply unpack the apk and grep for something like ://. For example
grep -R '://' ./unpacked-apk/*
Update: Added a tcpdump example.

I would recommend using Fiddler for this purpose, it is a tool that has a nice UI and you would not need to write any complicated command line commands. Here is a documentation article on how to configure Fiddler to capture traffic on Nexus device.

What is Apache-HttpClient/UNAVAILABLE error (Android, Google App Engine)?

I am confronting myself with a problem that I do not know how to interpret. I am doing a project using Android and Google App Engine. When I am trying to save information in Google App Engine's Big Table, directly from the servlet (hardcoded) - the save is performed with no problem. But when I am trying to save data from my Android device, the save is not performed and the log indicates Apache-HttpClient/UNAVAILABLE error. To be more specific:
405 55ms 0kb Apache-HttpClient/UNAVAILABLE (java 1.4)
82.155.246.249 - - [10/Jun/2013:05:20:59 -0700] "POST /servletnamehere HTTP/1.1" 405 306 - "Apache-HttpClient/UNAVAILABLE (java 1.4)" "appnamehere.appspot.com" ms=56 cpu_ms=21 cpm_usd=0.000034 app_engine_release=1.8.0 instance=00c61b117cede3f754aa1ece730dc88287a20199
I have seen that 405 HTTP error appears in the context of a POST method ( "405 errors often arise with the POST method. You may be trying to introduce some kind of input form on the Web site, but not all ISPs allow the POST method necessary to process the form." ) => indeed, I am trying to perform add (the object is a JPA Entity) in the database using a POST method. The data I am receiving from my Android device is serialized, through an input stream (in my case, working with JSON is not an option, these are the specifications).
Also, 306 HTTP error reffers to switch proxy. While the porevious error might be a bit intuitive, this one is beyond my student knowledge.
I have followed the instructions of this tutorial (http://trumpy.cs.elon.edu/joel/sigcse2011/), which is indeed what I need, but I really cannot figure out what I did wrong. I took again the procedure, stept by step, but I don't see the flaw.
Any help will be indeed appreciated. If I should post some code, I'll gladly do it.
Best wishes,
Cropcircles
LATER EDIT:
Now I get 417 HTTP error expectation failed. I have seen that I am supposed to set a certain parameter on false, but this workaround was available only for .NET. Is there anyone who knows what's the correspondent of the following, in Java? I am really really confused.
<system.net>
<settings>
<servicePointManager expect100Continue="false" />
</settings>
</system.net>

This is not an answer, but is too long for a comment and may be helpful, so here goes...
First, it's hard to tell what's going on here because there is limited info. Try to post more of the logging either on the client or on the server. Go to the server console and get more info, for instance, or add debugging in the client. I'd start by trying to make the POST from a debug/testing tool like hurl.it: http://www.hurl.it/ (hurl is a nice web front end to a command line HTTP client named curl, see curl itself if you want a more advanced peek). That way you can test and poke around and make SURE your server side works as you expect with a generic client. Then build other clients (like Android).
Second, "Apache-HttpClient/UNAVAILABLE" is not an error, it's just the user-agent String -- so ignore that part. (UNAVAILABLE is where the version typically is, but some impls don't have access to the version sometimes, it seems.)
Third, the 405 response code IS an error, it means POST is not allowed at the server you are trying to POST to. That can either be because POST is not allowed at all on said server, or you're violating some security policy (such as same origin).
If it's AppEngine, first check the APP you are using and make sure it supports POST (look for info on how to do POST at AppEngine to solve, for instance: google app engine: 405 method not allowed). When you say you can do it directly from a "servlet," do you mean that a POST from a different client works? (Servlet is a server side technology, so that's a little confusing.) If so then make sure your Android app is doing the client part the same way to the same host (multipart vs urlencoded, etc).
For a little more on the security stuff, which could be involved, see this post: Google App Engine + jQuery Ajax = 405 Method Not Allowed.

I've had the same trouble and in my case It was an error due to no write permission on server side area.
I was following an android test to write on a file a value transmitted in async way via POST method.
Apache received the POST request but was not able to write the data on the file due to security permission on it.

Android Rest client to Delphi XE2 Datasnap Rest server

I found many examples on Stack Overflow and I just don't know where to start since I have a particular prerequisite:
My Delphi Datasnap Rest server is using ZLibCompression and RSA encryption (in TTransportFilterCollection of DSHTTPWebDispatcher). Is there an Android restful API that can handle those? Any sample that already implements that?
I found this thread Android REST client, Sample? as a good starting point, both lightweight and well-formed clients are presented but is it enough for me?
Thanks in advance for any hint, sample or library that you could point me to.

you can use the Android Rest-Client for sending data to a webservice
see my answer in the post Adding body of call to POST using HttpURLConnection

I just used the proxy generator from Danasnap server TDSProxyGenerator component (http://yourserver:port/proxy/java_android.zip) and added this code to my android project...
I had to search for the DSRESTSSLFactory.java file that is not generated by the proxy (but required !!), i found it in a demo from embarcadero, and from that point the communication is entirely handled, all accessible procedures are publicated, and really really simple to use...

How to debug http calls on Android devices?

I'm writing a Lovefilm client for Android, and it's not going too badly except I keep having problems with the remote calls to retrieve data from the API.
Does anyone have any tips for debugging remote calls like this? Can I tcpdump on Android or is there a native way of doing it?
For example, I'm using the Scribe-java library for OAuth to access the Lovefilm API, I can authenticate find and retrieve a list of films on the users account fine when the device is running Gingerbread, but trying to retrieve the accessToken on Froyo causes a blank response & and apparent response code of -1, I'd like to be able to see what's going on under the cvers their.
Another example I'd like to be able to the raw http for is trying to run a search, I get and IOError that says "Received authentication challenge is null"

I've used Fiddler (http-proxy for debugging http calls) with the android emulator in these cases. Just start the proxy, and start the emulator with the correct proxy address (-http-proxy ).

Fiddler is the most useful option. On the emulator #Scythe answer will work, but on a real device you will need to set the proxy in the Apache Http Client. The following code will do that:
HttpHost proxy = new HttpHost("youripaddr", 8888);
params.setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);
If you are using https, fiddler is not so useful. In that case can enable the build in logging support in Apache Http Client. The following code does that:
Headers only:
java.util.logging.Logger apacheHeaderLog = java.util.logging.Logger.getLogger("org.apache.http.headers");
apacheHeaderLog.setLevel(java.util.logging.Level.FINEST);
Headers & Wire:
java.util.logging.Logger apacheWireLog = java.util.logging.Logger.getLogger("org.apache.http.wire");
apacheWireLog.setLevel(java.util.logging.Level.FINEST);
Note that this will have to have a java.util.logging Handler configured at finest level and the default handler is configured to log to logcat, which will filter DEBUG (finest) entries by default.

If your system can share the wi-fi connection you should be able to route packets from any device through your system and then using wireshark you can get monitor your calls or get a tcpdump.
Also , and more importantly , it would be best if you log your network calls and responses as suggested by #Matthew
Windows 7 wi-fi connection sharing : http://www.winsupersite.com/article/faqtip/windows-7-tip-of-the-week-use-wireless-hosted-networking-to-share-an-internet-connection-wirelessly.aspx

Since I always run into similar troubles and it seems a lot of people having the same issues over and over again I wrote up a quick tutorial for debugging client-server communication by using netcat and cURL.
That of course only works for the simplified case that you always 'fake' on side of the connection.
For eavesdropping you can use tools like tcpdump or Wireshark. Which will definitely be easier if you're able to run the server instance directly on your local machine.

Stetho is a great tool from FB which helps in debugging android Apps. You can have access to local data and have a check on your network using this.
http://facebook.github.io/stetho/